Apparatus for saving gold and other precious metals.



w. 0. M. HOWARD.

APPARATUS FOR SAVING GOLD AND OTHER PRECIOUS METALS.

APPLICATION mm MAR. 11. 1913. RENEWED JAN. 2a. 1918.

Patented Feb. 26, 1918.

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Application filed March 11, 1913, Serial No. 753,490. Renewed January 23, 1918.

WILLIAM D. M. HOWARD, OF SAN FRANCISCO,

CALIFORNIA, assreivon no HARRY DE COURCY RICHARDS, OF SAN FRANCISCO, CALIFORNIA.

APPARATUS FOR SAVING GOLD AND OTHER PRECIOUS METALS.

To all whom it may concern.

Be it known that I, WILLIAM D. M. How- ARD, a citizen of the United States, and a resident of the city and county of San Francisco, State of California, have invented new and useful Improvements in Apparatus for Saving Gold and other Precious Metals, of which the followin is a specification.

This invention re ates to improvements in the process of and apparatus for saving gold and other precious metals, and more particularly to the process of and apparatus for saving precious metals by amalgamation.

Among the many objects of this invention are:

To save the fine particles of metal by prolonging the interval of contact with the amalgamating medium.

To divide'the amalgamator into separate cells or pockets; to combine the maximum number of these cells in the minimum of space; to so shape these pockets that the hydrokinetic energy of the flowing pulp will cause mechanical separation of the particles forming the pulp and develop a marked vanning action of the particles as they overflow from one pocket to the next.

To introduce electric energy of high voltage and relatively low amperage in the process of saving gold.

To decompose the ferrous oxid or other coatings from the metallic particles by the addition of proper chemicals to the flowing pulp, cooperating with the electrical eflects to accomplish this object.

To alternately magnetize and demagnetize the apparatus, whereby the particles associated with magnetic or iron substances will be segregated from the constantly flowing pulp and be retarded in their passage through the amalgamator.

The invention possesses other advantageous features which, with the foregoing, will be set forth at length in the following description, where I shall outline in full that form of invention selected for illustration in the drawings accompanying and forming part of the present specification. The novelty of the invention will be included in the claims succeeding said description. From this, itwill be apparent that I do not restrict myself 'to the showing made by said drawings and description, as I may adopt Specification of Letters Patent.

Patented Feb. 2%, 191..

Serial No. 213,418.

many variations within the scope of my invention as expressed in said claims.

In the drawings:

The figure is a side elevation of an amalgamator constructed for operation in accordance with this invention. One-half of the amalgamator is shown in vertical cross section to disclose the contour-and correlation of the various parts. The electrical mechanisms are shown in diagrammatic relation therewith.

In detail the construction consists of the amalgamation mechanisms comprising the superimposed stationary annular cells 1, 2, 3, and 4, arranged in graduated descending heights in concentric series, and resting upon the wall 5 of the concentric launder or trough 6, which is in turn supported upon the insulated legs 7.

The receiving cup 8 has the overhanging flange 9 resting upon the neck 10 of the first cell. The pulp inflow pipe 11 depends con centrically into the receiving cup and discharges below the level of the overflow lip 12 thereon. The splash ring 13 is concentrically spaced from the receiving cup and rests upon the top of the abutting flanges 14: arranged on the radial lines of division between segments of the amalgamator when the latter is so constructed, or the ring may be otherwise supported.

In the smaller sizes it is practical to cast the amalgamating cone of an integral piece; however in the larger sizes, for obvious reasons, it is more practicalztov divide it into sections, concentrically or radially; these sections may be bolted together as shown, or so formed that they interlock without the use of bolts or the like.

The outer portion of the inner surface 39 of the cells 2, 3 and 4 is curved upwardly, inwardly and downwardly, so as to produce a Whirl of the pulp liquid in a vertical plane when it is introduced into the cells. Each of the cells has an overflow edge 38 which extends inwardly in the form of an annular flange which-overhangs the surface 39, the upper surface 37 thereof being upwardly and outwardly inclined in radial planes at an angle approaching the angle of rest of the heavier material in the pulp liquid.

The electrical apparatus preferably comprises the high tension insulator-15, mounted upon the pin 16 attached to the body of the amalgamator and which may be duplicated at suitable intervals. The cross arm 17 supported by the insulator in turn supports the bus bars 1S18, from which the discharge plates or electrodes, 19-19, are suspended by the straps 20-20. The electrodes 19 preferably hang ust above the surface of the flowing pulp, and center over the mass of quicksilver w,'eontained in the cell beneath. These electrodes can be duplicated over one or more of the cells in the series as circumstances require.

In the simpler forms of apparatus I use a common dry cell battery 21, a pendulum interrupter, an induction or Ruhmkorfl coil 22 preferably fitted with the vibrator 23. The current flows from the battery 21 tothe U bar 24 having the platinum contact points 2525. The opposite pole of the battery 1s connected to the pendulum 26 having the spring contact 27 adapted to make and break the battery circuit as the pendulum is swung back and forth by suitable movement contained in the box 28 upon which the pendulum is pivoted. When the battery circuit is closed by the interrupter, the current flows through the vibrator 23 energizing the primary windings in the coil 22 and inducing a current in the secondary w1ndings of the coil. One pole of the secondary preferably the negativeis connected over the cable 29 to the connection 29* on the amalgamating cone; the opposite pole is connected through the cable 30 to the insulated binding post 31 of the bus bars 1818,

thence to the electrodes 20.

Each swing ofthe pendulum closes the circuit and causes a high tension discharge across the amalgamating cell from the electrodes 20 to the amalgamating cone which forms the opposite pole of the circuit.

The soft gray iron body of the amalgamator is magnetized by the helix coil 30 surrounding the integral core 33 formed on the bottom of the iron receiving cup. This coil is energized from the battery through the wire 34 passing direct to the coil, thence through the wire 35 connected to the contact segment 36 fixed in the path of the pendulum. The opposite pole of the battery is connected to the insulated contact brush 36 on the pendulum which makes contact with the said segment as the pendulum passes the latter in its swing.

The above is a very simple and economicalform of electrical apparatus which can be substituted by various forms to suit circumstances in the practice of this invention.

This amalgamation apparatus is particularly designed to treat finely divided ore in the condition of flowing pulp and operates substantially as follows:

The pulverized ore and water, forming the pulp, is discharged through the pipe 11 into the receiving cup 8, from whence it overflows the inturned flange or lip 12 which subdues the boiling agitation of the pulp and causes it to flow outward in a substantially even sheet pouring into the first a1nalgamating cell. The splash ring 13 confines the flow from the receiving cup and causes it to drop into the first cell, in the event of too much pressure being applied to the flowing pulp. The agitation of the pulp in the receiving cup causes the smaller particles in suspension to pass out first, followed by the larger particles. These particles collect on the slightly upwardly inclined inner portion 37 of the upper surface of thelip 12 arid arrange themselves thereon, the smaller particles at the top of the incline, as in a vanning machine; thus arranged the particles are carried over the horizontal peripheral portion of the lip where a further vanning action occurs, and then over the edge 38 by the flowing water; the smaller particles, being in the lead, strike the quicksilver w first. As the particles of free gold are principally associated with the smaller particles, they reach the amalgamating agent and are absorbed thereby. The drop of the pulp eascading from cell to cell drives the metallic gold into the quicksilver, facilitating amalgamation and at the same time keepin the quicksilver in violent agitation or a ive and more effective for amalgamation.

The peculiar curved contour 39 of the interior of the cells causes the flowing pulp to return upon itself and dash again on to the surface of the amalgamating medium, repeating the operation many times before the initial force of the drop into the cell is dissipated, thus prolonging the interval of time in which the pulp and its gold particles are associated with the amalgamating medium, in the meantime maintaining a violent agitation which facilitates amalgamation.

This operation and eflect is duplicated progressively in each cell. The number of cells can be increased or diminished as circumstances demand. The height of the dro from the edge 38 to the surface of the ama gamating agent increases progressively, and whereby the diffusion of the pulp over a greater area-because of the increasing circumference coveredis compensated for by increasing the drop from cell to cell, to maintain the hydrokinetic effect as near uniform as may be. The vanning action is present in increasing proportion as the circumference of the cell increases.

The overflow from the last cell drops into the trough or launder 6 encircling the amalgamation cone, from which it is discharged through the chute 40.

To increase the amalgamating area by forming interstices or retaining pockets in the amalgamating medium, the segment of wire netting 41 is floated upon the surface eams? thereof. The interstices formed by the wire mesh act as rifiies to retain the gold particles.

Thus far is described 'a very effective mechanical amalgamating apparatus. mechanical results are greatly enhanced by the addition of electrical effects.

The negative pole of the high frequency circuit being connected to the amalgamating cone, the discharge is from the positive electrodes toward the negative. The discharge diifuses throughout the downflowing pulp, exerting a dynamic downward force on all metal particles suspended in the pulp, tending to drive them into the quicksilver, with obviously advantageous eflect's, in promoting amalgamation. There is present also a marked galvanic action tending to associate the metallic particles with the quicksilver. The flow or discharge of electric energy is intermittent, the interval being determined by the make and break contacts of the interrupter controlled by the pendulum or otherwise. While an induced magnetic condition exists in the amalgamating cone at the time of electric discharge from the electrodes to the amalgamatin cone, it is advantageous to increase this e feet by directmagnetization. The receiv ing cup is provided with a core extension surrounded by a helix coil as before described. The magnet thusformed is intermittently energized through the interrupter formed by the contacts 36- and 36 also controlled by the pendulum. This latter interrupter is so timed that the amalgamation cone is magnetized between the intervals of electrical discharge through the electrodes m. The efiect of this is to cause the magnetic particles associated with the gold particles to be attracted and held to the surface of the amalgamation cone, while the flow of the I gangue is uninterrupted. Just prior to the electric discharge from the electrodes, the magnetic circuit opens, demagnetizing the cone and releasing the attached particles, which are driven intothe quicksilver by the kinetic energy of the flowlng pulp and the dynamic force of the electric discharge as before described. The condenser action of the quicksilver, hysteresis, and-many other electric and magnetic phenomena are present and contribute to the increased saving of gold; but as they are the results of the associated elements of the invention, it is deemed unnecessary to discuss them herein.

Much of the metallic gold iscoated with ferric (Fe fl or (MnO and other salts, in which condition it resists amalgamation with the quicksilver. To overcome this 'condition, I introduce a suflicien-t quantity of common salt (NaCl) which, being taken in solution by the water, and disintegrated by the high pressure electric discharge liberates nascent chlorin and chlorin gas. 7

Tn the action the gold passes from the These 7 anode into the chlorin solution when the v AuCI H+H :Au-i-4HCL With certain ores cyanid of potassium may be used advantageously under the influence of an electrostatic discharge. Under 7 the influence of this discharge with cyanid of potassium in solution both the coarse and float gold are compelled to remain longer in the neighborhoodof the anodes where it is chemically dissolved artly by direct contact and partly by the place. under the conditions produced 'in this apparatus and process, the following reactions are cited:

- I claim:

1. In an apparatus ofthe character described, an annular cell having a curved bottom wall, and'an inwardly extending annular overflow lip havin a flat upper surface inwardly inclined slightly to the horizontal and a curved under surface overhanging the cell.

2. Tn an apparatus of the character described, an annular cell. having a curved bottom wall, an inwardly extending annular overflow lip having a flat upper surface inwardly inclined slightly to the horizontal and a curved under surface overhanging the outer edge of the cell, and means for feeding liquid to the inner edge.

3. A gold saver comprising a series of concentric cells in step formation, a substantially parabolic receiving cup having an inwardly overhanging overflow lip' and adapted to overflow into the topmost cell in said series, and a splash ring spaced from said cup above said topmost cell.

4. A gold saver comprising a series of cells in step formation with graduated height-s of risers, each cell having an inwardly overhanging lip with a top surface alogens here liberated. To illustrate the/reactions taking cell downwardly along its inclined upward from the body of the cell and joining the floor of the cell in a curved line, the cell floor and the riser to the next cell forming substantially a parabolic curve.

&

extending inwardly from the outer overflow edge of the cell, the upper surface of said flange being upwardly and outwardly inclined in radial planes at an angle approaching the angle of rest of the heavier material in the liquid pulp.

6. In an apparatus of the character disclosed, a stationary annular overflow cell, an annular flange extending inwardly from 10 the upper edge of an annular upright wall of the cell, the upper surface of said flange being inclined inwardly slightly to the horizontal.

In testimony whereof, I have hereunto set my hand at San Franclsco, California, this 5 28th day of February, 1913.

WILLIAM D. M. HOWARD. In presence of- BALDWIN VALE, P. S. PIDWELL. 

